Mushroom’s labours are in the dark

In truth, I had no idea how tricky landing those chlorophyll deprived fungi on your dinner plate were. I spent my childhood tirelessly searching for an elf under them, only always to fall short. So I set about, being the fun-guy I am, to delve into the enormous challenges that face the mushroom grower and put pay to 30 odd years of naivety.

Buttons are taken first to thin the crop & leave space for field mushrooms to develop

Mushrooms have become the third most valuable vegetable crop in Australia with only tomatoes and potatoes presenting greater value. Some government studies of new horticultural industries have proclaimed the mushroom industry to be one of the three most successful newer agricultural industries in Australia.

To be economically viable, nearly all local production is absorbed by the domestic market as fresh produce, with less than 10% of Australian grown mushrooms being used in processing.

With the rise in appreciation of the health benefits of mushrooms and the growth of Asian cooking appeal within the country, the industry has been growing at a faster rate than most other agricultural industries. This increase has largely resulted from improved productivity and efficiency on existing farms.

Mushrooms are now often grown on shelving

Expenses are massive. As with so many crop growing businesses, mushroom growing as an industry is a significant employer and very labour intensive with the requirement to pick every mushroom by hand. Another major expense to absorb is in the supply of the growing media due to the governmental prevention of the grower producing their own media within urban dwellings. Organic wastes from other primary industries are used in the production of the substrate in which include wheat straw and poultry manure. If not recycled, these materials can pose potential environmental threats, so they are blended together and organically substrated to produce a nutrient-rich medium in which to grow mushrooms. However, such processing has inevitably produced a conflict that has impacted on the mushroom grower as a result of this process due to the odour by-products. Odour produced in the making of mushroom substrate has led to the control of producer’s locations and thereby resulted in the reduction in the number of substrate producers over recent years, as farmers cannot economically make and transport their own substrate and therefore buy this in from substrate media producers.

Mushroom spores spread through the growing media

This has taken to great extent the quality control of the substrate mix out of the grower’s hands. As a mushroom grower, the quality of the mix made will only show up weeks into the growing cycle of the mushrooms to which a poor quality substrate can have major effects on the yields at a point when the producer can do little about it. Production cannot be altered with a poor batch of mix and the grower must absorb those losses.

‘Pinning’ process underway

Mushroom growing has become one of most technologically sophisticated horticultural practices in the country. Ironically, the mix used to grow them could not be any cruder and as such to date, there has been no scientific advances on a suitable substitute for the current one. In this day and age, it could be said that the mushroom industry could hold its head high as few horticulture industries, absorb and use as much waste product.

Mushrooms double in size each day following emergence

Mushrooms are grown in confined rooms in which the environment is precision controlled to provide ideal growing conditions. Keeping the air conditioned to the correct needs of the growing spores is not a meagre expense to the grower. Constant checks ensure that temperature, air composition and humidity are kept at the right levels as the spawn grows through the substrate. At every stage of the process, the environment is carefully monitored and hygiene strictly controlled. Diseases and hygiene management rise to the surface of priorities to the grower, and losses in yield due to the transfer of disease by the presence of unwanted vectors in flies for one example, cannot be understated. Staff are also major carries of pathogens that can rapidly diminish a yield and result in poor quality mushrooms.

Water is critical & must be precise. With the primary harvest, the water quantity must be even & added at the exact volume of the mushrooms harvested

Mushroom growers have made big investments in climate-controlled growing environments specifically designed for mushrooms to ensure that quality fresh mushrooms are available for
consumers every day of the year. However, weather and seasons do have a major effect on the quality of the substrate media made, with winter producing far better media and resulting in better quality mushrooms.

One or two thoughts that cross my mind now as to the perils of life as a mushroom grower as I fill those brown paper bags at Coles…..

6 thoughts on “Mushroom’s labours are in the dark”

After the mushrooms are harvested the strata is often sold off as mushroom compost for the garden. We buy large quantities at a time and stockpile it in a dark place and grow more mushrooms from this strata before we use it to mulch and topdress our vegetable garden where inevitably we get more mushrooms growing. It’s a win-win situation for we veggie gardeners and I haven’t bought bagged mushies in over a year since I learned about this from a fellow veggie gardener…fresh mushrooms…cheap good quality mulch and more mushrooms as a prospect? What’s not to love! Cheers for this enlightening post and for sharing some information about my passion, mycology 🙂

Hi Matthew,
I live in Bilpin within the Hawkesbury local govt area, somewhere where mushrooms have been grown for many years. The industry has come up against all sorts of challenges due to the outward march of housing.
We used to find it pretty easy to order a big truck load of spent mushroom compost for the garden – beautiful stuff. Recently the answer was no, we can’t do it. I can see the clash between new housing developments and intensive agriculture, but…….I wish you the best.

Had no idea there was so much to growing mushrooms. Seems perilous. Thanks for an invigorating post, Matthew. I looove mushrooms. Long may the mushroom growers thrive and do hope the industry endures. I also love what mushroom compost does for the garden. I have not had the emergence of mushrooms that narf7 has, but am grateful for this rich, nourishing substance.

Neither did I Julie. The farmer I went to see was in his 70’s and been growing them for 40 odd years. I doubt if he has had a day off in that time. Mushrooms have a very different perspective on the dinner plate now!!